Heretofore, a method for manufacturing a three-dimensional shaped object by irradiating a powder material with a light beam has been known (such method can be generally referred to as “selective laser sintering method”). The method can produce the three-dimensional shaped object by an alternate repetition of a powder-layer forming and a solidified-layer forming on the basis of the following (i) and (ii):
(i) forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam, thereby allowing a sintering of the predetermined portion of the powder or a melting and subsequent solidification of the predetermined portion; and
(ii) forming another solidified layer by newly forming a powder layer on the formed solidified layer, followed by similarly irradiating the powder layer with the light beam. See JP-T-01-502890 or JP-A-2000-73108, for example.
This kind of technology makes it possible to produce the three-dimensional shaped object with its complicated contour shape in a short period of time. The three-dimensional shaped object can be used as a metal mold in a case where inorganic powder material (e.g., metal powder material) is used as the powder material. While on the other hand, the three-dimensional shaped object can also be used as various kinds of models or replicas in a case where organic powder material (e.g., resin powder material) is used as the powder material.
Taking a case as an example wherein the metal powder is used as the powder material, and the three-dimensional shaped object produced therefrom is used as the metal mold, the selective laser sintering method will now be briefly described. As shown in FIGS. 6A-6C, a powder layer 22 with its predetermined thickness is firstly formed on a base plate 21 by spreading powder 19 through a movement of a squeegee blade 23 (FIG. 6A). Then, a predetermined portion of the powder layer is irradiated with a light beam “L” to form a solidified layer 24 (see FIG. 6B). Another powder layer is newly provided cn the solidified layer thus formed, and is irradiated again with the light beam to form another solidified layer. In this way, the powder-layer forming and the solidified-layer forming are alternately repeated, and thereby allowing the solidified layers 24 to be stacked with each other (see FIG. 6C). The alternate repetition of the powder-layer forming and the solidified-layer forming leads to a production of a three-dimensional shaped object with a plurality of the solidified layers integrally stacked therein. The lowermost solidified layer 24 can be provided in a state of being adhered to the surface of the base plate 21. Therefore, there can be obtained an integration of the three-dimensional shaped object and the base plate. The integrated “three-dimensional shaped object” and “base plate” can be used as the metal mold as they are.